Molding-knife protractor.



PATBNTED JUNE 16, 1903.

A. F. NYE. MOLD'ING KNIFE PROTRACTOR.

APPLIUATION FILED JUNE 9, 1902.

N0 MODEL.

O @fm vgya 'fmg m;

.protractor for determining the proper contour UNITED STATES Patented June 16, 1903.

PATENT OEEIc-E.

ALVIN F. NYE, OF ROCHESTER, NEW YORK, ASSIGNOR TO WALES M. NYE.

MoLDlNc-KNIFE PRoTRACToR.

SPECIFICATION formingpart of' Letters Patent No. 731,066, dated une 16, 1903.

Application. filed June 9,1902. Serial No. 110,866. (No model.)

To @ZZ 1071.071?, t may concern:

Beit known that I, ALVIN F.'NYE, a citizen of the United States, and a resident of Rochester, in the county of Monroe and State of NeWYo1k,have invented certain new and useful Improvements in Molding-Knife Protractors, of which the following is a specification.

This invention relates to a molding-knife of the knives used on machines for cutting moldings and like articles whereby with a pattern of any cross-section the. pantograph automatically gives the contourof the knifeedge with which such pattern can be cut. Heretofore the edges of molding-knives have been determined by a laborious cut-and-try method and are not truly accurate. By this machine, however, the form ofthe knife-edge is accurately determinable.

In the drawings, Figure lis a top plan view of the device. Fig. 2 is a side elevation. Fig. 3 is an enlarged cross-section on the line 3 3 of Fig. 1. Fig. 4 is an enlarged View of one end of the members of the pantograph, and Fig. 5 is a cross-section of the head of a molding-machine having a knife attached thereto and showing its relation to a molding in process of being cut. Y

As shown by Fig. 5,v the heads A of moldingmachines are squared and are provided with means, such as T-slots ct, whereby the knives may be attached to them. The shaft A passes through the axis of the head. The knife Bis attached to one of the flat sides of the square head by means of a bolt h in a manner well known. The heads A are from three to four inches square. The knife B, being* fastened on one of the iiat sides of the head, is always at an angle of the surface of the formed molding in order that its cutting edge should operate properly upon thewood and should have proper clearance, and said knife extends more or less beyond the corner of the head, so as to give chip-clearance to the extent of the needed depth to be cut into the blank from which the molding is formed. The vertical dotted line in Fig. 5, running from the arc of the circle that indicates the swing of the head and knife, represents the extreme depth of cut of the knife B, and it will be seen that the knife when cutting the upper edge of the molding had already finished its cut on the lower edge oc thereof. In other words,

lthat portion of the knife which cuts deepest of the shaft shows by its angle with the firstmentioned dotted line the dierence of position of the extreme cutting edges of the knife and shows that the contour of the knife-edge must differ by'just so much from the rightangled cross-section of the molding. In Fig. l the full lines in the upper right-hand corner represent the form of the knife-edge, and the adjacent dotted lines represent the crosssections of thermolding and show the difference between the molding contour and the contour of the knifefedge. These lines differ from each other, as shown in Fig. l, the line representing the knife-edge having more curvature than the dotted lines representing the molding.

The pantograph, proportioned for use-with heads of three to four inches square, is made as follows: On a suitable base C a rod D of any suitable length is fastened by supports d. On this 'rod V slides'a sleeve E, which sleeve may move longitudinally along the yrod and may'also rock. This rocking is most easily provided for by making the rod D cylindrical; but the rod D may have any non-cylindrical contour fitting the sleeve E, provided in this case. The rod may rock in its bearings d.

To thesleeve E isl rigidly fastened the trans-y verse base-arm F. To this base-arm are pivoted three bars. At one end is Vthe pantograph-bar G, pivoted at g', on the end of which is carried a marking-point g. The distance-from the axis of the shaft D to the pivot-point g' of the arm'G on the arm F is two inches. From the axis ot' the bar D to the pivotal point h of the arm H on the arm F is three and five-sixteenths inches. 0n the same side as the arm H there is pivoted the arm J at a distance of one and three-fourths inches from the axis of the bar D. The arms J and H are pivoted to the arm F on aline at right angles to the bar D and eleven-sixteenths of an inch to the right on the parallel linepassingthroughthepivotalpoint g. The

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K, pivotedto each thereof at the points k, j, and h, so that said arm K is at right angles to the line of the bar D when in the position of the arm J shown in the drawings. The markingpoint g is one and twenty-three thirty-seconds inches from the pivot 7c. The bar H, however, is pivoted to said bar K at a point h, which is four and one-fourthinches from the pivot 7c, while the pivot 71, is five and five-sixteenths inches from the axis of the bar G. The arms G, F, H, and K constitute a quadrilateral polygon with unequal sides, one of which sides (the bar F) is moved in a straight line on the bar D. The tilting of the bar F is only a matter of convenience and is not functional. The end of the bar J carries a tracing-point .J' at a distance of threeeighths of an inch from the pivotal ceuterj. 'Thev pivots g',j', h', h, and 7c are permanent.

The pivotal points g' and h are five and eleven thirty-seconds inches apart, the points h and 7L are four and one-halt' inches apart, the points h and k are four and one-fourth inches apart, the points g and k are five inches apart, andthe distance from g to j' is three and three-fourths inches, while the distance from 7i: to j' is variable from three and nineteen thirty-seconds to four inches for a purpose now to be explained.

For a head four inches square I provide a slightly-curved slotj2 (having a line-of-beauty curvature) in the center of the arm J, through which the thumb-screw pivot-ping' may pass. The arm Jfor better bearing rests,as shown in Fig. 3, between two plates, one of which is the arm K and the other of which is a plate K beneath said arm Kaud rigidly fastened thereto, so that said arm J extends between said two plates, and the pivot-pinj passes through a perforation in the arm K, through the slotjz, and being screw-threaded on its lower end engages similar screw-threads in said lower plate K. It' said pin j passes through the slotj2 and the tracing-point J' is swung laterally, (up and down in Fig. 1,) the pin will slide along the slot j?. The similar slots js and i4 (one on each side of the slot jg) in the form of device shown are provided for drafting the edges of knives for attachment to heads of other sizes, because it will be seen that if the pin j is placed in the slot jsand the tracing-point is placed at a certain position the marking-point g will be farther from any hase-line parallel to the line of the bar D, and therefore will produce a Wider knife, While if the pin]l is in the slot l7'4 the back edge of the knife will be nearer to the cutting edge, and the knife drafted will be suitable for still another head.

On the bar lo may be a caster L for facilitating the movement of the mechanism.

Upon the bed C of the machine are means for fastening thereon a knife-contour plate X. For this purpose I prefer two stops M M and a clamping device N, which may consist of a spring that is adapted to be fastened to the base C by means of a screw n and can be adj usted for pressing the plate X-between the spring N and the stops M M. may be of paper or wood or may be a metal plate, such as zinc, and the marking-point g may be of steel, so as to mark the contour of the knife edge with accuracy. Upon the base C also are suitable devices for clamping the pattern thereto, such as the iieXible strips O O, fastened to said board at one end by the screws 0 and at the other end by the thumbscrew o', so that the paper pattern Ymay be clamped to the base C, as shown in Fig. 1.

It is customary to set the knife to register with the edge of one of the faces of the head A, and in order to adapt this pantograph to this custom I set one of the stops M in such a position that the end of the knife-contour plate X'shall register with the outer edge of Asaid stop M, as shown 'at the right hand of Fig. l. On the base C is marked a corresponding line indicated by the arrow, (at right angles to the base,) which is as far distant from the corresponding line passing ing-point J in the position shown in the drawings is from a line passing through the markving-point g at right angles to the bar D. The

pattern Y is so adjusted with reference to this line indicated by the arrow that the co1'- responding side edge of the molding-pattern shall have the right distance from said line to permit the knife-pattern drawn therefrom to have the proper adjustment just described with reference to the end of the head A.

It will now be seen that from the construction described the pantograph-frame may be moved sidewise or in line with the guide-bar D without relativevchange of the tracing-point J and the marking-point g, but that lateral movements transverse to the line ofthe-guidebar D will cause slight changes of the marking-point g with reference to the tracingpoint J', and that as .the tracing-point J appreaches the base-line Zmarked on the board C the marking-point g Will proportionately increase its travel over the travel of the tracingpoint J', so that the line marked by it will be nearer to thebase-line, and as the pantograph is swung in theopposite direction and the tracing-point J/ follows the contour on the molding-pattern Y the knife-edge drafted by the marking-point g will as it moves farther from the base-line Z increase the distance from said base in proportion to the motion of the tracing-point J This increase and decrease is due to two facts-the dilerent lengths and the lack of parallelism of the arms Gr Yand H and the fact that the arm J is maintained nearly but not quite parallel with the arm Gr, the variation in parallelism being controlled by the contour of the slots y2, dac., on each side of a line in or parallel to a line joining the pivotal centers j' and .7'.

The device may be enlarged or reduced in substantially the proportions stated, and the increase or decrease of movement of the point g with reference to the point J maybe varied.

The plate X- through said edge of the stop M as the traclOO ' connection.

2. In a pantograph for substantially the purposes described, a straight-line-guiding device,a membersupportedthereon and transversely thereto, two bars of unequal lengths pivoted on said member and extending in the same direction therefrom, a bar pivotally connected to said two bars and thereby forming a quadrilateral figure having unequal sides and a fth barpivoted to said first-mentioned member and having a slot-and-pin connection to the last-mentioned bar.

3. In a pantograph for substantially the purposes described, the combination of a quadrilateral frame pivoted at its corners, having one member supported on a straightline-guiding device, in combination with a bar pivoted to said member by a fixed pivot and to the opposite member by a slot-and-pin connection havingatracing-point on its outer end and a marking-point on the outer end of a member of said frame parallel, in one position, to said bar.

4. In a pantograph for substantially the purposes described, a straight-line-guiding device,a member supported thereon and transversely thereto, two bars of unequal lengths pivoted on said member and extending in the said direction therefrom, a bar pivotally connected to said two bars and thereby forming a quadrilateral iigure having unequal sides and a ifth bar pivoted to said first-mentioned and to the opposite member by a slot-and-pin connection, a base, a clamping device on said base for the pattern and a clamping device for the copy embodying guiding means therefor.

6. In a pantograph for substantially the purposes described,a straight-line-guiding device, a member supported thereon and transversely thereto, two bars of unequal lengths pivoted on said member and extending in the same direction therefrom,a bar pivotally connected to said two bars and thereby forming a quadrilateral figure having unequal sides and a fth bar pivoted to said first-mentioned member and having a slot-and-pin connection to the last-mentioned bar, a base, a clampingdevice on said base for the pattern, and a clamping device for the copy embodying guiding means therefor.

7. In a pantograph for substantially the purposes described, the combination of a quadrilateral frame pivoted at its corners,hav ing one member supported on al straight-lineguiding device, in combination with a bar pivoted to said member by a fixed pivot and to the opposite member by a slot-and-pin connection having a tracing-point on its outer end and a marking-point on the outer end of a member of said frame parallel, in one position, to said bar, a base, a clamping device on said base for the pattern and a clamping device for the copy embodying guiding means therefor.

8. In a pantograph for substantially the purposes d escribed,a straight-line-guiding device, a member supported thereon and transversely thereto, two bars of unequal lengths Apivoted on said member and extending in IOO 

